1. Field of the Invention
This invention generally relates to a video signal processing apparatus and, more particularly, to a magnetic recording/reproducing apparatus for recording/reproducing a video signal, which can be a incorporated in camera built-in video tape recording/reproducing apparatus (VTR).
2. Description of the Related Art
Camera built-in VTRs have recently been developed. Some camera built-in VTRs incorporate a character signal generating circuit to display a title and a date on a camera EE image or a reproduced image. Generally, a character signal generating circuit separates the horizontal and the vertical sync signals from an EE video signal or a reproduction signal, obtains the horizontal and the vertical positions of an image by using horizontal and vertical counters, and sets a display position for the character information, thereby inserting the character information in the video signal.
According to a recently developed apparatus, when a character display is to be performed, characters are displayed in color or displayed in white or with a white frame.
Characters can be relatively easily colored by manipulating the R, G, and B signals, for example during a recording operation the R signal could be set at logic "1" (high level) and outputs corresponding to the G and B signals could be set at logic "0" (low level). In this case, an R (red) signal would be recorded at a character position.
In reproduction, a title or date is sometimes inserted in the signal. In some camera built-in VTRs, camera circuits are turned off during reproduction in order to save power. In such an arrangement, the above-described system of inserting character information in a video signal cannot be employed.
In certain camera built-in VTRs, the R, G, and B signals cannot be easily extracted by video signal processing circuit. If primary color (R, G, and B) filters are used in an imaging section, extraction of the R, G, and B signals can be easily performed. However, if filters of intermediate colors such as cyan and magenta are used, an arithmetic operation of a video signal must be performed to obtain the R, G, and B signals. In this step, coloring of character information is performed. Thereafter, the R, G, and B signals must be converted into the (R-Y), (B-Y), and (G-Y) color difference signals. In this case, in order to stabilize hues, a phase-locked loop must be added, thus complicating the system.
As described above, especially in the conventional camera built-in VTRs, no technique is available which can be suitably used to add colored character information in both recording and reproduction modes. To easily add color image information added in both recording and reproduction modes conventional video signal processing apparatuses in, a great change in existing video signal processing technology is required.